Blackberry White Chocolate Mousse Cake
Both elegant and heavenly, this Blackberry White Chocolate Mousse Cake features moist and tender vanilla cake, blackberry white chocolate mousse, and luscious blackberry topping!
Ingredients
Cake:
- ¾ cup + 2 Tablespoons all-purpose flour
- ½ teaspoon baking powder
- ¼ teaspoon baking soda
- ⅛ teaspoon salt
- 6 Tablespoons unsalted butter, softened
- ½ cup granulated sugar
- 1 egg
- ⅓ cup sour cream
- 1 teaspoon vanilla
- ⅛ teaspoon almond extract
- 1 Tablespoon lemon juice
- 1 Tablespoon lemon zest
- ¼ cup milk
Blackberry Topping:
- 4 cups blackberries (fresh or frozen)
- ⅔ cup granulated sugar
- 3 Tablespoons cornstarch
- ⅛ teaspoon of salt
- 2 teaspoons lemon juice
Blackberry White Chocolate Mousse:
- ½ cup blackberry topping (from recipe above)
- 3 cups heavy cream, divided
- 12 ounces white chocolate, chips or chopped
- 4 teaspoons unflavored gelatin
- 3 Tablespoons cold water
To Decorate:
- Freshly-whipped cream
- Fresh blackberries
- White chocolate curls*
Instructions
Make the Cake:
- Preheat oven to 350ºF. Line a 9-inch round cake pan with parchment paper and spray with nonstick cooking spray.
- In a mixing bowl, whisk together the flour, baking powder, baking soda, and salt until combined; set aside.
- In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and sugar together on medium speed until lightened and creamy. Beat in the egg until combined, scraping down the sides and bottom of the bowl as needed. Beat in the sour cream, vanilla, almond extract, lemon juice, and zest on medium speed.
- Pour the dry ingredients into the wet ingredients and mix until combined. Add the milk and mix until just combined, scraping down the sides and bottom of the bowl as needed.
- Pour batter into prepared pan, smoothing out evenly. Bake for 18-22 minutes, or until a toothpick inserted in the center comes out clean. Allow to cool completely before flipping out of the pan and onto a wire rack.
- Once completely cool, wrap a sheet of acetate (or parchment paper) about 6 inches tall around the edges of the cake to create a "wall". Secure the cake in a cake ring or springform pan that's at least 6 inches tall.
Make the Blackberry Topping:
- In a medium saucepan, heat the blackberries over medium heat until they soften and their juices start to release, about 3-4 minutes. In a separate bowl, combine the sugar, cornstarch, and salt. Add mixture to the blackberries and continue cooking until it begins to thicken, about 2-3 minutes. Pour into a shallow bowl and stir in the lemon juice. Place in the refrigerator to cool completely.
Make the Mousse:
- Place a fine mesh sieve over a bowl. Pour 1/2 cup blackberry topping into the sieve, straining out the seeds and solids. Set strained berry sauce aside.
- In the chilled bowl of a stand mixer fitted with a whisk attachment, beat 2 cups of the heavy cream until stiff peaks form. Set aside in the refrigerator.
- Place white chocolate into a medium bowl. Pour 1 cup of the heavy cream into a saucepan and heat until it begins to simmer. Immediately pour hot cream over the white chocolate and cover with plastic wrap. Let sit for 5 minutes. Remove plastic wrap and stir until completely smooth.
- In a small bowl, sprinkle the gelatin over the water; let stand 1 minute. Heat in the microwave for 10-15 seconds until gelatin is completely dissolved and liquified. Stir gelatin liquid into white chocolate mixture; allow to cool slightly.
- Fold 1 cup of the whipped cream into the white chocolate mixture to lighten it up. Then fold in the strained berry sauce until mostly combined. Add the rest of the whipped cream, folding until just combined. Spread mousse evenly over the cake. Chill in the freezer for about 15-20 minutes.
- Spread the blackberry topping evenly over mousse layer. Chill cake in the refrigerator until set, about 4 hours. I recommend an overnight chill.
Decorate the Cake:
- Once cake is completely set and firm, remove the cake ring (or springform pan) and the acetate (or parchment paper). Carefully transfer cake to a platter. Decorate with freshly-whipped cream, fresh blackberries and white chocolate curls.
Notes
*To make the white chocolate curls, I ran a vegetable peeler along the edges of a white chocolate bar.